Updated the `SceneTree.quit()` method to include a note that on iOS this method won't work as apps are expected to be closed via the Home button, not programmatically.
Update Popup.xml
Quits the application at the end of the current iteration. Argument [code]exit_code[/code] can optionally be given (defaulting to 0) to customize the exit status code.
By convention, an exit code of [code]0[/code] indicates success whereas a non-zero exit code indicates an error.
For portability reasons, the exit code should be set between 0 and 125 (inclusive).
+ [b]Note:[/b] On iOS this method doesn't work. Instead, as recommended by the iOS Human Interface Guidelines, the user is expected to close apps via the Home button.
Nick Huelin